4/16/2007 @ 12:10PM

In Pictures: The World's Cleanest Cities

#1 Calgary, Canada

Population: 988,193

Metro area: 5,107 square km

Calgary is the fastest growing city in Canada and has been known in the past as a center for oil and gas. Today it has taken on an added attraction in sports and is becoming more sought by tourists. It has light manufacturing. It was chosen by the Economic Intelligence Unit as a leading city to live in.